Problem: Gabriela had to do problems 45 through 75 for homework tonight. If Gabriela did all of the problems she was assigned, how many problems did she do?
Explanation: Instead of counting problems 45 through 75, we can subtract 44 from each number so we instead consider problems 1 through 31. We see that Gabriela did 31 problems. Notice that she did 31 and not 30 problems.